Finding onion sets that are firm, viable, and actually the correct day-length type for your northern garden can feel like a gamble. A bag of dried-out husks or mislabeled short-day bulbs wastes weeks of prime planting weather and kills your spring harvest before it starts.
I’m Mohammad Maruf — the founder and writer behind Gardening Beyond. I spend my time comparing seed stock viability rates, analyzing germination data across hundreds of customer reviews, and studying how supplier handling practices affect bulb dormancy and sprout success for northern gardeners.
This guide walks through the top-rated bulbs available right now so you can choose with confidence. My goal is to help you find a reliable batch of best long day onion sets that will actually perform in your northern plot without the guesswork.
How To Choose The Best Long Day Onion Sets
Your northern garden’s latitude determines how much daylight your onions receive during the growing season. Long-day varieties need 14 to 16 hours of sun to trigger bulb formation, so picking the wrong type leads to tiny bulbs and leafy tops come harvest time.
Day-Length Classification Is Everything
Long-day onions are bred for gardens above the 36th parallel. If you plant a short-day or intermediate variety in a northern zone, the plant will prioritize leaf growth over bulb swelling because the days never get short enough to signal bulb formation. Always verify the listing states “long-day” or check the recommended USDA zones before ordering.
Bulb Firmness and Viability
Sets that arrive soft, shriveled, or crumbly have already lost too much moisture to produce a healthy plant. Look for reviews that mention firm, plump bulbs with a weight that feels dense for their size. Avoid batches where multiple customers report desiccated or hollow sets — this is a sign the supplier stored them in hot or dry conditions for too long.
Quantity vs. Quality Tradeoff
Some packs ship 60 to 100 bulbs, but a high count means nothing if half are unplantable. A smaller package of 40 to 60 sets with a proven 90%+ germination rate outperforms a bulk bag where 30% crumbles on arrival. Focus on the ratio of viable bulbs per dollar, not the raw count.
Quick Comparison
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| Model | Category | Best For | Key Spec | Amazon |
|---|---|---|---|---|
| Smoke Camp Crafts Red Onion Sets | Long-Day | Northern red onion growers | ~100 bulbs, long-day variety | Amazon |
| Stargazer Perennials Yellow Stuttgarter | Intermediate-Day | Mild sweet flavor in varied zones | 50-60 non-GMO bulbs, 8 oz | Amazon |
| Stargazer Perennials Mixed Assortment | Mixed-Day | Diverse harvest from one pack | 50+ mixed red, white, yellow bulbs | Amazon |
| CaribbeanGarden Mix Onion Sets | Mixed-Type | Budget-conscious bulk planting | 40 bulbs, red, white, yellow mix | Amazon |
| Starting Gardens White Onion Sets | Long-Day | White onion preference in spring | 60-80 white bulbs, 16 oz | Amazon |
In‑Depth Reviews
1. Smoke Camp Crafts Red Onion Sets
The Smoke Camp Crafts package delivers roughly 100 red onion bulbs explicitly labeled as a long-day variety, which is exactly what northern gardeners need. The quality feedback is consistently strong: reviewers describe the sets as uniform in size, firm to the touch, and ready to sprout within days of planting. The packaging also uses natural materials, which helps preserve bulb moisture during transit.
At 80 to 100 days to maturity, these onions are a reliable mid-season crop for zones with cooler summers. The seller includes clear spacing instructions of 12 to 15 inches apart in full sun, and the bulbs are deer resistant — a practical advantage for unprotected beds. A small minority noted a few non-starters, but overall viability runs high based on aggregated feedback.
For a dedicated long-day red onion at a competitive per-bulb cost, this is the most consistent option. The uniform sizing and high sprout rate make it an easy recommendation for anyone tired of receiving mixed or mislabeled sets that fail to bulb properly in northern conditions.
What works
- Explicitly long-day variety for northern gardens
- High bulb firmness and uniform sizing reported
- Careful natural packaging reduces transit damage
What doesn’t
- A few bulbs may fail to sprout in every batch
- Red variety only — no color mix
2. Stargazer Perennials Yellow Stuttgarter Onion Sets
This 8-ounce package from Stargazer Perennials contains 50 to 60 USA-grown Stuttgarter bulbs, a premium yellow variety known for its mild sweetness and excellent storage longevity. Multiple customer reports confirm that nearly every bulb is firm and viable, with one reviewer counting over 120 mixed sizes including many marble-sized sets ideal for full-size bulb production.
Although labeled as an intermediate-day variety, northern growers in zones with moderately long days still see strong performance thanks to the Stuttgarter’s genetic reliability. The slow-bolting trait gives you a wider harvest window, and the bulbs store for months without softening. The sold-out listing for Washington and Idaho is a sign of high demand in northern regions.
The main downside is the batch inconsistency: a few customers received sets that were overly desiccated, with one reporting 80% crumbled. This appears to be a luck-of-the-draw issue with certain shipments. Overall though, the positive germination rate and flavor quality make these a top tier pick for cooks who want sweet storage onions.
What works
- Superior keeping quality for long-term storage
- Mildly sweet flavor ideal for cooking
- High germination rate with mostly firm bulbs
What doesn’t
- Intermediate-day type, not pure long-day
- Some shipments arrive with dry, crumbled bulbs
3. Stargazer Perennials Mixed Onion Assortment
This mixed assortment packs red, white, and yellow varieties into one 8-ounce bag, giving you a diverse harvest from a single purchase. The seller states the mix includes long-day, intermediate, and day-neutral types, which makes it suitable for zones 3 through 10. Customer reviews are overwhelmingly positive, with many noting that every single set sprouted within days of planting.
The bulbs consistently arrive firm and plump, far superior to the dry husks often found at local nurseries. One reviewer mentioned the mix leaned heavily toward yellow onions with fewer reds, so if you need a specific color ratio, this may not deliver balance. Still, the overall germination rate reported is exceptionally high, often reaching 100% in ideal conditions.
Where this set falls short is the lack of day-length specificity. While it works across many zones, a pure long-day designation would give northern gardeners more confidence. If you’re okay with a mixed-day gamble that historically performs well, this is a versatile and budget-friendly choice.
What works
- Excellent germination rate with plump, firm bulbs
- Three color varieties in one bag
- Suitable for a wide range of USDA zones
What doesn’t
- Color ratio can be uneven (mostly yellow)
- No pure long-day guarantee for northern zones
4. CaribbeanGarden Mix Onion Sets
This 40-bulb mix from CaribbeanGarden offers red, white, and yellow sets at a low entry point, but the reviews reveal serious risks. One verified buyer explicitly stated the seller confirmed these are short-day onions, which means they will not bulb properly for northern gardeners above the 36th parallel. The same reviewer reported only 10% sprouted with zero growth from the yellow bulbs.
On the positive side, other customers received the advertised 40 sets and observed all of them sprouting. The organic material and sandy soil compatibility are nice details, but the shipping experience is a recurring problem: bulbs arrived squashed in thin plastic mailers with no padding, and delivery took over two weeks. A few sets were dried and non-viable on arrival.
The low cost is tempting, but the combination of mislabeling risk, slow shipping, and inadequate packaging makes this a gamble. If you do order, plant immediately and hope for the best — but northern gardeners should exercise caution given the short-day confirmation from the seller.
What works
- Very affordable entry price
- Some batches show 100% sprout rate
- Organic material feature noted
What doesn’t
- Confirmed short-day type — wrong for northern zones
- Poor packaging leads to bulb damage
- Slow shipping with inconsistent viability
5. Starting Gardens White Onion Sets
This bulk pack from Starting Gardens ships 60 to 80 white onion bulbs in a 16-ounce bag, making it one of the largest counts in this roundup. Customer reviews highlight a 75% to 98% germination rate, with many reporting vigorous green growth within a week of planting. One buyer received double the advertised quantity, suggesting generous overfill from this supplier.
The bulbs arrive firm and fresh, ideal for both green onion harvests in 4 to 5 weeks or full dry onions by late July. The spacing recommendation of 2 to 4 inches apart allows for dense planting in raised beds or containers. A rare negative review claimed zero sprouting and suspected gassing, but this appears to be an outlier against dozens of positive experiences.
For northern gardeners specifically seeking white onions with reliable growth, this pack delivers strong viability at a low per-bulb cost. The main limitation is color — no mix means you commit to white onions for the entire season. If that suits your cooking needs, the value and germination consistency are tough to beat.
What works
- High germination rate consistently reported
- Generous overfill in many shipments
- Bulbs arrive firm and ready to sprout
What doesn’t
- White variety only — no color options
- Rare reports of gassed bulbs with zero sprouting
Hardware & Specs Guide
Day-Length Classification
Long-day varieties require 14 to 16 hours of daylight to initiate bulb formation, making them ideal for northern gardens above the 36th parallel. Intermediate and short-day types will produce tops but fail to size bulbs properly in these regions. Always verify the listing specifies “long-day” or check USDA zone compatibility before purchase.
Bulb Firmness and Storage Conditions
Sets should feel dense and plump, not hollow or crumbly. Dried-out bulbs indicate poor storage at high temperatures or low humidity. A firm bulb retains enough energy to push through early growth. Bulbs that arrive soft or shriveled have less than 50% viability and should be returned or composted.
Maturity Timeline
Long-day onions typically require 80 to 100 days from planting to full bulb maturity. Some varieties like Stuttgarter mature slightly faster and offer slow-bolting genetics for a wider harvest window. Green onions can be harvested in 4 to 5 weeks if you prefer scallions over dry bulbs.
Quantity vs. Viability Ratio
A pack of 40 firm bulbs with a 95% germination rate outperforms a pack of 100 bulbs where 30% crumble on arrival. Focus on the ratio of viable sets per dollar, not the advertised count. Read recent reviews to check for batch consistency before ordering large quantities.
FAQ
What is the difference between long-day, intermediate, and short-day onion sets?
How can I tell if my onion sets are still viable before planting?
Can I plant long-day onion sets in containers or raised beds?
Why did my onion sets sprout leaves but never form bulbs?
Final Thoughts: The Verdict
For most northern gardeners, the best long day onion sets winner is the Smoke Camp Crafts Red Onion Sets because it offers a pure long-day variety with consistently firm bulbs and high germination feedback. If you want a mildly sweet storage onion, grab the Stargazer Perennials Yellow Stuttgarter. And for a budget-friendly white onion with solid viability, nothing beats the Starting Gardens White Onion Sets.